Automatic calling device



April 7, 1925. 1,532,677

.J. BLESSING AUTOMATIC CALLING DEV ICE filed Feb. 2, 1921 Julm Efilsssm afl. Z. BIZ y:

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Jenn e. stnssrus, or crrroneo, ILLINOIS, rarrr, or cnroaeo, rumors,

ASSIGNOE 'IO AUTOMATIC ELECTRIC CORI- A OQR-PORATION OF ILLINOIS.

AUTO'VIATIG CALLING DEVICE.

Application filed February To all whom it may concern:

Be it known that I, JOHN G. BLESSING, a citizen of the United States of America, and a resident of Chicago, Cook County, and State of Illinois, have invented certain new and useful Improvements in Automatic Calling Devices, of which the following is a specification.

My invention relates in general to automatic calling devices and more specifically to an improved type of impulse sending mechanism for use in transmitting calling impulses to control the operation of an automatic switch of any well known two wire yr Among the features of my invention are to provide a simply constructed and simply operating device of the character described,

which is easy to manufacture and operate when installed.

Among the further features is to provide a simple method of prolonging the interval of time between the transmission of thefinal impulse of one digit and the transmission of the first impulse of the succeeding digit. It is well known that such a calling device is used in practice to first send one series of impulses to cause the vertical motion of the standard two wire Strowger selector, and the switch then operates automatically to select an idle trunk in the group elected. Therefore sufficient time must be given to permit this automatic trunk selecting function before the next series of impulses are In order to accomplish the above result the finger dial is made larger than usual, and has a longer space between the No. 1 finger hole and the finger stop. It will be understood that were no special means provided to prevent it, this dial when operated by the first finger hole would move its cam a suificient distance to send two impulses or one entraimpulse for each series dialled. Means are provided as will be explained for preventing the transmission of this extra impulse by moving the cam out of the path of the impulse springs at a critical time. Gther features of improvement will be explained in the following detailed description of the accompanying drawings in which:

Fig. 1 is a front view of the device with the plate 2 (Fig. 2) removed.

Fig. 2 shows the plate 2 covering the front of the dial. r

2, 1921. Serial 1 Io.441,938.

Fig. 3 is a top view of the device showing the impulse and shunt springs and their 'relation to the impulse cam or interrupter.

Fig. 4 is a rear view of the device showing the governor and related devices.

Fig. 5 is a front view of the device with the finger dial and number plate removed showing the operating gears.

Fig. 6 is a rear view of the finger hole dial showing the gear and ratchet devices mounted on the rear thereof, the gear'being partly cut away to show the ratchet.

Fig. 7 is a side view of the governor. 7

Figs. 8 and 9 are detailed views of the interrupter cam and its unit assembly showing how the cam and gear are operated to eliminate the final impulse to prolong the time interval between any two successive seies of impulses.

I will now describe the features and method of operation of this calling device more in detail.

This calling device comprises the usual finger hole dial 1 mounted on a plate 3. This plate 3 is a casting formed from any light and durable material and is so simply designed that it requires no machine operations except the threading of certain holes. The various mounting lugs are formed in the casting and thus the device is very simple of construction and has very few detachable parts.

The finger dial 1 is mounted by means of a screw 4. to the plate 3 and carries a power spring?) one end of which is attached to a lug on the side of screw t and the other end of which is fastened to one of the lugs 6 turned up from the dial 1. The dial 1 has .a longer space between the number 1 finger hole and the finger stop than is usual in such dials, this space being so proportioned that the dial by means of its gears always rotates the impulse cam one extra revolution for each digit, which last revolution is however, rendered ineFectiVe as will be explained. A combined pawl and stop 7 is pivoted at 8 on the dial and has two teeth Q'and 10 cooperating with the ratchet wheel 1%. An arm 11 of this ratchet 7 extends towards the circun'iference of the dial and lies in the path of a stop pin 12 projecting l ll) to meet the stop pin 13 in the dial. This gage with the gear 30 whiclis also a part movement of the arm 11 is just sufiicieut to cause pawl 10 to disengage tro-m the teeth or" ratchet wheel Li and cause fl to. en-

gage said teeth to thus posi stop me dial and the ratchet. The sp mg 12 norinally tends to hold the pawl ment with the ratchet teeth 11 away from the stop pin 3.

l the teeth it and upon the return nioveine oi the dial the pawl engages said e to cause ratchet 14: to be rotated liacl-zwarn with the dial.

The cover plate 2 (Fig. 2) is slotted and fits over the front of the linger dial to cover all parts thereon and is held in place by a screw 15..

@n the back of the plate o are mounted the interrupter sorings lo and 1'! and the shunt springs 18 2111C- Th. springs 16 and 1'? are opened 1n the ope ztion oi? the mounted on its shaft and revolves freely in one (llfQCt lOlL The pawl spring 2 is 1 the teeth of a ratchet wheel 2 so that when the revolve the governor carried with them but when the gears come to a positive step saic. governor may rotate on freely until it con to a stop ot its own accord, thus preventing any strain on the governor. v

In 5 are shown the giurs lo v \vhscl the THOYQIDGDt ot the dial is communicated to the cam 20.

The cam and the gear 26 are mount (l on opposite ends of an enilwise movahle shaft 2'4, the spring 19 normally tending to force the slatt 2i inward. On the under side of the cial is mounteo. a rounded lug 28, (Figures 3, 8 and 9) which i des over the rounded surface of the gear s the dial rotates through the final portion of its movement just hetore reaching normal, thus torcing the shaft outward against the tension of spring 19 to move the cam outward and pre vent its engagement with the springs 16 and 17 and also to open the springs 18 and 19. lfhus it will be seen that even though the cam has one extra revolution, this last revolution does not send an impulse by opening springs 16 and 17. Cooperating with the teeth of gear 26 is a loosely mounted gear and pinion 29 the pinion teeth of which ena comloined gear and ratchet and which is loosely mounted on a sleeve 31 on the dial 1. The sleeve fits the threaded. stud and the mechanism is all held inplace by screw at- (Fig. 1). he gear 33 of the governor also ineshe 'with the teeth of the gear undernea h the piece which held to the plate 3 by screws and terms a pivot point for the gear andpinion by means of armature 35.

Thus the: dial when rotated forward stores tension in spring 5 and ratchet 1O rides over wheel 1st without in ving said wheel. The amount of force required to operate the wheel 1-; 'must be sutiicient to also operate the entire connected gear train and the tension of the spring 12 being very slight is net ally not sullicicnt to do this; however, it the wheel 1% should happen to start to turn, the back of the cam 20 will engage the back of the impulse springs and prevent further movement of the wheel. its the dial returns the wheel 'l-l is rotated with the dial by ratchet 10 carrying also gear 30. The movement is communicated through gear 30, pinion on gear gear 29, gear 26 to the cam 20 thus interrupting springs 16 and'lf a number of times. The movement is governed by the action governor, the parts 22 being thrown out'hv centrifugal force and rubbing on the wall to retard movement.

As the dial nears normal posit-ion log 28 rides upon gear 26 and moves the cam 20 out-vard so that the last revolution ot the cam does not operate the The shunt springs 18 and it) are opened h this movement of cam 20 tl insu that the last'impulse has been sn'iittea.

t will thus he seen that l have provided a cry etiicicnt and simply constructed type of calling device which delays the transmission of th first digit of any. impulse a certain length 01" time after the transmission of the last impulse of a preceding die-it and which has other features and details of improvement which will pointed out in the appended claims.

What I claim as my invention is:

endwise, a rotatable linger hole dl a pro ection on said dial directly engagng said gear, said pro ection moving Si'lt gear sprin s 16 and 1?.

ratchet wheel and means efi'ective at another time to cause the other end of the pawl to engage said ratchet Wheel.

3. In a calling device, a rotatable'finger hole dial, a ratchet wheel mounted adjacent thereto, a double ended pawl mounted on said dial, one end thereof normally engaging the teeth of said ratchet wheel so that the wheel is carried with the dial when rotated in one direction, and means for causing the other end or said pawl to engage the teeth of said ratchet wheel to stop the wheel.

4. In a calling device, a rotatable finger hole dial, a ratchet wheel mounted adjacent said dial, a combined pawl and stop mounted on said dial, said pawl having one arm cooperating with the teeth of said ratchet to drive the ratchet, another arm co-operating with the teeth oi the ratchet wheel to stop theoperation of the wheel, another arm and means for operating it to render said second arm effective.

5. In a calling device,-a rotatable finger hole dial, a movable member carried by sai-t dial, a linger stop having an auxiliary stop, a spring attached to said dial normally tending to rotate the same, and a fixed member on the dial for preventing the rotation of said dial by its engagement with said movable member, and by a resultant engage-- ment of said movable member with said auxiliary stop.

6. In a calling device, a rotatable finger hole dial, a toothed wheel, a finger stop proviled with an auxiliary stop, a movable member carried by said dial and having a plurality of arms, one of said arms normally engaging said wheel to prevent its rotation in one direction while another of said arms engages said auxiliary stop to prevent the rotation of said dial, and means including aspring attached to said dial for maintaining said arms in the afore mentioned position.

7. In a calling device, a rotatable finger hole dial, a toothed wheel, a finger stop provided with an auxiliary stop, a movable member carried by said dial and having a plurality of arms, one of said arms nor mally engaging said wheel to prevent its rotation in one direction while another of said arms engages said auxiliary stop to prevent the rotation of said dials, means including a spring attached to said dial for maintaining said arms in the ai'ore mentioned position, and means on said dial released whenthe dial is rotated for moving said member to an alternate position to cause another arm to engage said wheel to cause the same to be rotated by power stored in said spring when the dial is released.

8. In a calling device, springs lying in one plane, a shaft having spring operating mechanism fixed to one end thereof and a wheel on the other end thereof, a rotatable finger hole dial having a cam mounted thereon, said cam normally engaging said wheel to hold the operating mechanism associated with said shaft in another plane, means for moving said operating meclranism into the plane in which said springs are'lying when the dial is rotated in one direction, and a gear train for rotating said operating mechanism to operate said springs when the dial is rotated in the reverse direction.

9. In a calling device, impulse sending mechanisms, driving mechanisms therefor, a finger hole dial, a spring wound up by the forward movement of the dial, which returns the dial to normal, a combined pawl and stop associated with the dial and controlled by the-return thereof to operate said mechanisms, said pawl and stop operated when the dial reaches a predetermined position to stop both the dial and the mechanisms.

10. In a calling device of the rotatable dial type, a stop lined to the frame, a lever pivoted on the dial and adapted to engage said stop during the return 01 the dial to normal, and a second stop fixed to the dial and adapted to engage said lever after the same has engaged said firs-t stop.

11. In a. calling device comprising a rotatable dial and a. sending mechanism, a gear train for operating the sending mechanism when the dial returns to normal, a stop fixed to the frame, and a lever pivoted to the dial and operated by. said stop when the dial reach-es normal position to stop said gear train.

Signed by me at Chicago, Illinois, this 13th day of January, 1921.

JOHN Gr. BLESSING. 

